How the World Time Zones Tool Works
Learn how to use the world time zones tool to track multiple time zones, schedule meetings, and coordinate across different regions worldwide.
A complete guide to the world time zones tool. Learn how to add up to six cities, read the 24-hour timeline with work-hours shading, use the grid and difference views, and find the best meeting times with the planner. Covers Daylight Saving Time handling, future-date scheduling, and the copy-to-share meeting summary feature. Free, no sign-up, no app install.
Key Features
- Adding and managing up to six cities for comparison
- Timeline view with 24-hour bars and work-hours shading
- Grid view with analog clocks and current local times
- Difference view showing hour offsets between city pairs
- Meeting Planner with configurable work-hours window
- Daylight Saving Time handling using the IANA timezone database
- Future-date scheduling and timeline scrubbing
- Copy-to-share meeting summary for cross-timezone coordination
Frequently Asked Questions
How do I add cities to the world time comparison?
Click the "Add City" button and search for any city by name. You can add up to six cities simultaneously. Each city you add appears in all views — Timeline, Grid, Difference, and Planner — with its current local time displayed in real time. To remove a city, click the X icon next to its name. Your selected cities are saved locally so they persist when you return.
What is the Timeline view and how do I read it?
The Timeline view shows a 24-hour horizontal bar for each city, with work hours (9 AM–5 PM by default) shaded in a lighter color and the current time marked with a vertical line. This lets you visually scan for overlapping work hours across all selected cities — where the shaded regions align, everyone is in work hours. You can drag the timeline scrubber to any past or future date to see how the overlap changes.
How does the Meeting Planner find the best meeting times?
The Planner tab computes every hour where all selected cities are within your configurable work-hours window (default 9 AM–5 PM). It ranks the results by how many cities are in work hours at that time, so if no full overlap exists, it shows the next-best partial overlaps. For each suggested time, it lists each city's local time side by side. You can adjust the work-hours start and end times to match your team's schedule.
How do I share meeting times with participants in different time zones?
In the Planner tab, click "Copy Summary" to copy a plain-text breakdown of the best meeting times to your clipboard, showing each city's local time side by side. Paste it into an email, Slack, or WhatsApp message. Every participant sees their own local time in the same message, eliminating the back-and-forth of "what time is that for you?"
Does the tool account for Daylight Saving Time?
Yes. The tool uses the IANA timezone database to compute each city's actual UTC offset for the specific date you select. When a city transitions into or out of DST, its offset changes by one hour, and the tool reflects this automatically. This is why the time difference between two cities can change by 1–2 hours twice a year — the Planner tab always shows the correct overlap for the date you choose, even on the day of a DST transition.
Can I check what time it will be in another city on a future date?
Yes. Use the date picker or the timeline scrubber to move to any past or future date. The tool recalculates every city's local time for that date, including any DST transitions that occur between now and then. This is useful for scheduling meetings days or weeks ahead, since the UTC offset for some cities changes on DST transition dates.
What is the Difference view?
The Difference view shows the hour offset between every pair of selected cities in a compact table. For example, if you have New York, London, and Tokyo selected, it shows that New York is 5 hours behind London, London is 9 hours behind Tokyo, and New York is 14 hours behind Tokyo. This is useful for quickly understanding the gap between cities without looking at a full timeline.
Is the world time zones tool free to use?
Yes. The tool is entirely free, requires no account, no sign-up, and no app install. It runs in your browser and your selected cities are saved locally on your device. Nothing is sent to any server.